It is desirable to control infection at the site of implantation of a medical device. In surgical procedures for the replacement of an orthopaedic joint, it is known to provide an antibiotic material within a bone cement composition.
It is known to provide an antibiotic material in a coating on the surface of a medical device. US-A-2007/0050010 discloses a vascular implant such as a stent having a coating which can contain a drug. A protective polymer layer can be provided on the coating to prevent degradation of the drug coating. The polymer can control the rate at which the drug in the coating is absorbed into the patient's bloodstream.
It can be desirable in order to minimise infection risk for an antibiotic in an implant coating layer to be released quickly after implantation.
The present invention provides an implantable medical device in which a drug coating layer has an overlying protective polymeric layer, in which the layer comprises polylactic acid, polyglycolic acid or a lactic acid/glycolic acid copolymer having a weight average molecular weight of not more than 40,000.